氧化铝-氧化镁非晶陶瓷的中温塑性变形及应变强化  

Moderate-temperature Plastic Deformation and Strain Hardening of Amorphous Al_(2)O_(3)-MgO Ceramics

作　　者：王江林 苏兴华[1] 张业翔 胡永彪[2] 许西庆 WANG Jianglin;SU Xinghua;ZHANG Yexiang;HU Yongbiao;XU Xiqing(School of Materials Science&Engineering,Chang'an University,Xi'an 710061,China;School of Construction Machinery,Chang'an University,Xi'an 710061,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]长安大学工程机械学院,西安710064

出　　处：《中国陶瓷》2023年第7期41-45,52,共6页China Ceramics

基　　金：国家自然科学基金(52102062);陕西省重点研发计划(2020KW-036)。

摘　　要：脆性是陶瓷的致命弱点,实现陶瓷塑性变形一直是结构陶瓷领域的关键问题。实验旨在探究Al_(2)O_(3)-Mg O非晶陶瓷的中温塑性变形,利用溶胶凝胶法制备Al_(2)O_(3)-Mg O非晶粉体,通过热压成型技术获得结构均匀致密的非晶陶瓷,并在500~700℃进行单轴压缩测试。Al_(2)O_(3)-Mg O非晶陶瓷在500℃表现为脆性断裂,在600℃呈现9.7%的塑性变形,变形前后始终保持非晶态;700℃的塑性变形为7%,而且在变形中析出Mg Al_(2)O_(4)晶相并产生应变强化。不同于Al_(2)O_(3)-Mg O非晶陶瓷,同组成的多晶陶瓷未能发生塑性变形。非晶结构是发生塑性变形的基础,非晶相通过形成大量的剪切带容纳剪切应变从而成为宏观塑性变形的关键。Brittleness is the fatal weakness of ceramic materials,and the achievement of plastic deformation in ceramics has been the key issue in structural ceramics.This paper is aimed at probing into the moderatetemperature plastic deformation in amorphous Al_(2)O_(3)-Mg O ceramcis.Amorphous Al_(2)O_(3)-Mg O powders were synthesized by sol-gel method,and consolidated into homogenous and dense amorphous ceramics by hot pressing,then uniaxial compression was carried out on the amorphous ceramics at 500~700℃.Even though the amorphous Al_(2)O_(3)-Mg O ceramics are brittle at 500℃,they exhibited plastic deformation of 9.7%at 600℃and remained uniform amorphous throughout the deformation.The plastic strain at 700℃was 7%,during which Mg Al_(2)O_(4) crystallite were precipitated and resulted in strain hardening.In contrast to amorphous Al_(2)O_(3)-Mg O,the polycrystal ceramics with the same composition displayed no plastic deformation.The foundation of plastic deformation is credited to the amorphous structure,and the abundant shear bands formed in amorphous phase accommodated shear strain and became the key to macroscopic plastic deformation.

关 键 词：非晶 塑性变形 Al_(2)O_(3)-MgO 应变强化 剪切带 

分 类 号：TQ174.758.11[化学工程—陶瓷工业] TB383[化学工程—硅酸盐工业]